[Dovecot] Dovecot performance under high load (vs. Courier)

[Wojciech Puchar]

>>> But I don't know, whether this is the sort of caching you are referring 
>>> to.
>> 
>> what's a point of caching imap, except your webmail service is not locally 
>> connected (localhost or LAN) to imap server?
>
> Asking for items 600-615 from a threaded list, sorted by something, can be an 
> expensive operation, especially if you just asked for items 585-600 a moment 
> ago?
>
fine. how about overhead of cache itself?